Traditional building management systems for regulating heating and ventilation are closely integrated to, and communicate with, the technical systems for lighting, access control and security, thereby creating increased efficiency.
TAC Sweden initiated a dialogue with Malmö Municipality about what to expect from a supplier of building management systems and solutions. The initiative led to a vision document describing key areas to be focused upon during the next few years. The most important priority was the energy efficiency of existing buildings, owned and managed by Malmö Municipality.
Energy costs in Sweden had increased by 40% during the previous four years and in light of the EU directive on energy conservation it was crucial to become pro-active in this area. The second priority identified was how to create a school environment for the future and how these new schools could be optimised both in terms of energy efficiency and indoor climate, security and safety.
TAC proved to be a strong partner for both these priorities. The Strand School in Klagshamn, just outside Malmö city centre, is the first project where systems and solutions for energy conservation, indoor climate and security issues were considered as opportunities to take building management systems to a new level.
The solution
The general concept behind the technical installations at the Strand School is that traditional building management systems for regulating heating and ventilation are closely integrated to, and communicating with, the technical systems for lighting, access control and security, thereby creating increased efficiency in terms of operations and possibilities for energy conservation.
One of the main benefits created through this coordinated approach is that components, (eg, for motion detection), can be co-utilised by the security system as well as by the technical systems controlling the indoor climate.
Additionally, the fact that one supplier provides all the technical systems in the building leads to improved coordination during the planning and construction phase. An open communication between the existing systems also enables further benefits by sharing vital information that traditionally resided in closed and separate systems. For example, the security system informs the ventilation system that a window in a classroom is open, which consequently signals the ventilation system in that particular room to switch to standby mode, thereby saving energy.
Access control and security
The school in Klagshamn is equipped with an access control system based on TAC’s I/NET solution. During after-school hours, students and staff can enter the building by using their access card together with an individual PIN-code. The school is divided in such a way that the alarm system for each zone can be individually activated or de-activated.
At 16:00h, all main doors in the hallways are closed by automatic release of the magnetic contacts holding them. This ensures that the building is ready to be locked down completely without having to close doors manually in order to avoid alarms. At 18:00h, a voice message is broadcast throughout the building via the PA system, announcing that the building is about to be closed and the alarm is being turned on.
Staff remaining in the building can prolong their stay by entering their individual PIN code at the closest card reader. Motion detectors used to operate the ventilation system during the day are used by the intrusion alarm system to monitor movement in the building after hours.
When a zone’s alarm system has been activated, the lighting in that section is automatically turned off in order to save energy. If an alarm is activated, the lighting turns on for the whole zone to ensure that guards and/or police have easy access to the premises. This co-utilisation of components traditionally reserved for the security system, such as motion detectors and magnetic door and window contacts, makes for efficient, intelligent building management.
A typical room
The benefits of an integrated and coordinated approach for the building systems become clearly evident when looking at the features and functionality of a typical room in the school. All areas throughout the building operate in the same manner, with the co-utilisation of components and sharing of vital information.
During nights and weekends, when the building is locked down and the alarm system is activated, a typical room is set to standby mode. At 07:30h, all rooms are automatically set to economy-mode, which means 19°C and minimal airflow.
Once someone enters the room, it goes live: the motion detection device activates the room and sets it to comfort mode. Temperature is increased to
21°C and airflow is increased.
As more people enter the room, the temperature and carbon monoxide monitoring devices continuously measure and optimise the airflow and radiators to constantly keep a pre-set temperature and a safe level of carbon monoxide. Once a window is opened, it is indicated by the intrusion alarm system through the magnetic contacts in all windows. This is communicated simultaneously to the heating and ventilation system and the room switches to standby mode after one minute; ventilation and radiators turn off automatically, to conserve energy. When the window is closed again, the system resets to comfort-mode.
When everyone has left the room, the lights are automatically turned off after 20 minutes, thanks to the integration between the security system (motion detectors) and the lighting system.
The highly integrated building management system makes it possible to conserve energy and ensure optimised operation of the building’s technical systems. This is made possible through the tight integration between the lighting, indoor climate and security systems. Management is made easy through a single user interface with TAC Vista. Users can access the system on site, or via a Web interface where both TAC engineers and the technical staff at Malmö Municipality can monitor and optimise the solution.
For more information contact Nico van der Merwe, Schneider Electric, +27 (0)11 254 6400, [email protected], www.schneider-electric.co.za
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